updated README.md.
Added install notes, server redirect, and changed zbarServerURL to a functioning server. Folder example-ajax-client renamed as ajax, and python-server renamed as server.

Added install notes, server redirect, and changed zbarServerURL to a functioning server. Folder example-ajax-client renamed as ajax, and python-server renamed as server.

Added install notes, server redirect, and changed zbarServerURL to a functioning server. Folder example-ajax-client renamed as ajax, and python-server renamed as server.